The present invention relates to a method for controlling a device system, which includes a tool device and a motorized advancing apparatus, during the machining of a workpiece composed of a first material and a second material different from the first material.
With respect to machining tool devices, various materials that are to be machined, for instance concrete and steel, require adjusted machining parameters. The machining parameters adjusted to the respective material differ strongly from one another due to the various material properties of concrete and iron. The machining parameters include not only a suitable machining tool, but also, for instance, torque and rotational speed with which the machining tool is driven around an axis of rotation.
In order to take advantage of the available power of the tool device and at the same time reduce wear and tear on the machining tool, it is known that the operator will adjust the machining parameters of the tool device to the machining tool and the material of the workpiece. For core bore devices, for instance, the parameters of the drive motor, especially the power and the rotational speed, are set as a function of the diameter of the core bore bit. The disadvantage is that an inexperienced operator does not have the necessary knowledge to adjust the machining parameters of the tool device to various materials. In addition, it is frequently not known where reinforcing bars are located.
From EP 1 988 438 A1 is known a method for controlling a device system consisting of a device stand, a tool device, and a motorized advancing apparatus as well as a corresponding device system for executing the method. The tool device includes a drive motor for driving a machining tool, a sensor apparatus for measuring the motor output, and a control unit for controlling the tool device. The motorized advancing apparatus includes, among other things, an advancing motor and a control unit for controlling the motorized advancing apparatus. A known control method has the disadvantage that the control of the overall device system takes place exclusively on the basis of the motor output or a measurement value functionally dependent on the motor output. The advancing speed is determined from the motor output. The motor output and the advancing speed determined from it serve to estimate the tool parameters (bore bit diameter) and workpiece parameters (height of the workpiece and concrete or iron). On the basis of the estimated tool and workpiece parameters, target values are determined for the rotational speed and the motor output of the drive motor while using lookup tables containing know-how about the machining method.
The present invention, in contrast, consists of further developing a method for controlling a device system which includes a tool device and a motorized advancing apparatus so that the machining parameters are adjusted to the properties of the workpiece to be machined and the machining process for core boring is largely automated.
This task will be accomplished for the aforementioned method for controlling a device system, which includes a tool device and a motorized advancing apparatus according to the invention.
In accordance with the invention, a method for controlling a device system, which includes a tool device and a motorized advancing apparatus, during machining of a workpiece composed of the first material and a second material different from the first material, is disclosed. The workpiece is machined by the device system initially in a first operating mode with first machining parameters that are stored for the first material. After the start of the machining of the workpiece in the first operating mode, a first machining progress of the tool device is measured and stored as a reference value. During machining of the workpiece in the first operating mode, a current machining progress of the tool device is regularly measured and compared with a first threshold value.
The present invention relates to the machining of workpieces that consist of various materials. The workpieces exhibit at least two different materials that are referred to as the first and the second material and that differ from each other in their material properties. The material located at the surface of the workpiece is referred to as the first material. The combination of materials most important for core boring is concrete as the first material and iron as the second material, whereby iron is embedded in the concrete in the form of reinforcing bars.
A prerequisite condition for the method according to the invention is that the device system knows the materials of which the workpiece to be machined consists and which material is located on the surface of the workpiece. For various materials, appropriate machining parameters are stored in the device control of the device system, first machining parameters for the first material and second machining parameters for the second material. The stored machining parameters are based on a variety of bores and are stored in the form of lookup tables in the device control. The machining parameters stored in the device control can be optimized with respect to various basic conditions such as the frequently applied basic conditions include high machining speed, low tool wear, and high machining quality.
In order to be able to automatically control the device system which includes the tool device and the motorized advancing apparatus, the device system must recognize whether the bore bit is machining the first material of the workpiece or the second material of the workpiece. With respect to the control method according to the invention, it is assumed that the workpiece at the surface consists of the first material. Therefore, the device system is initially machined in a first operating mode with first machining parameters that are stored for the first material. After the start of machining in the first operating mode, a first machining progress is measured and stored as a reference value. As a bore progress, a quotient made up of a path difference and a time difference is defined which therefore represents a speed. The bore progress thus can be calculated so that the positions of the bore bit are measured or the necessary time is measured for preset positions of the bore bit at the start and at the end of a fixed time interval.
Machining in the first operating mode starts at a time when it is ensured that the first material is machined. The decision of whether the bore bit will machine the first material or the second material is made with the assistance of the bore progress. During machining of the workpiece in the first operating mode, a current machining progress of the tool device is regularly measured and compared with a first threshold value. The first threshold value, like the machining parameters, is based on a number of bores and is stored in the device control. The first threshold value includes the various material properties of the first and second material.
The workpiece is further machined by the device system in the first operating mode when the current machining progress is within the first threshold value. Because the first material is not homogenous, smaller deviations of the current machining progress from the reference value are permitted. As long as the deviations are smaller than a permitted deviation, the machining will take place with the device system in the first operating mode.
The device system is switched from the first operating mode to a second operating mode when the current machining progress is outside the first threshold value, whereby the workpiece is machined by the device system in the second operating mode with second machining parameters that are stored for the second material. Because the properties of the first and second materials differ strongly from each other, there is a dramatic change in the current machining progress when the bore bit machines the second material. This change in the current machining progress is used to switch from the first operating mode to the second operating mode.
In a first embodiment, the first threshold value is smaller than the reference value. The workpiece is machined in the first operating mode as long as the current machining progress is less than the first threshold value. When the current machining progress is less than the first threshold value, the device system is switched from the first operating mode to the second operating mode.
In a second embodiment, the first threshold value is more than the reference value. The workpiece is machined in the first operating mode as long as the current machining progress does not exceed the first threshold value. When the current machining progress exceeds the first threshold value, the device system is switched from the first operating mode to the second operating mode.
During machining of the workpiece in the second operating mode, the current machining progress of the tool device is regularly measured and compared with a second threshold value. The second threshold value, like the machining parameters and the first threshold value, is based on a number of bores and is stored in the device control.
The workpiece is further machined by the device system in the second operating mode when the current machining progress is within the second threshold value. Because the second material is not homogenous, smaller deviations of the current machining progress are permitted. As long as the deviations are less than a permitted deviation, machining takes place with the device system in the second operating mode.
The device system is switched from the second operating mode to the first operating mode when the current machining progress is outside the second threshold value, whereby the workpiece is machined by the device system in the first operating mode with the first machining parameters that are stored for the first material.
In the first embodiment in which the first threshold value is less than the reference value, the second threshold value is greater than the first threshold value. The workpiece is machined by the device system in the second operating mode as long as the current machining progress does not exceed the second threshold value. The device system is switched from the second operating mode to the first operating mode when the current machining progress exceeds the second threshold value.
In the second embodiment in which the first threshold value is greater than the reference value, the second threshold value is less than the first threshold value. The workpiece is further machined by the device system in the second operating mode if the current machining progress does not exceed the second threshold value. The device system is switched from the second operating mode to the first operating mode when the current machining progress is less than the second threshold value.
The method according to the invention can be applied to workpieces having more than two materials. A prerequisite condition is that for each material suitable machining parameters are stored and there are corresponding threshold values that represent the transition between two materials.
Embodiments of the invention are described below by way of the drawing. The drawings are not necessarily meant to represent the embodiments to scale but rather, the drawings, where useful for explanatory purposes, are provided in a schematic and/or slightly distorted form. With respect to additions to the teachings directly discernible from the drawing, reference is made to the relevant prior art. Here it is important to note that a variety of modifications and changes can be made with regard to the form and detail of an embodiment without deviating from the general idea of the invention. The features of the invention disclosed in the description and/or the drawing can be essential individually as well is in any combination for refining the invention. In addition, all combinations of at least two of the features disclosed in the description and/or the drawing fall within the bounds of the invention. The general idea of the invention is not limited to the exact form or the detail of the preferred embodiments shown and described below. For given measurement areas, values within the stated limits are to be disclosed as threshold values and arbitrarily usable. In the interests of simplicity, the same reference numbers are used below for identical or similar parts or parts with identical or similar function.